Burglar-alarm



.\ and it has for its object to provide a simple, economical and dent of Milwaukee,

U T D 1$TA E PATENTQFFIC'E;

JOHN s. srmswxa zra, or 'iiuLwAUx E, DANIEL c. OCONNELL AND ONE-THIRD WAUKEE, sconsin.

To all whom it may concern: V

Be'it knownthat I, JOHN S.. SrIREWKn, J13, a citizen of the United States, and resiin the county of M11- mukee'and .Stateof Wisconsin, have nvented certain new and useful Improvements in Burglar-Alarms; and I do'hereby declarethat the followingis a full, clear, and. exact description thereof.

My invention refersto burglar alarms,

effective audible signal alarm attachment for standard door knobs or windows.

The specificobject of my: invention provideanalarm that can bereadflymounted upon a door and. associated with the knob shank thereof, whereby an actuating camcan be detachably mounted upon the knob shank to thus set off the alarm when the knob is rotated. V

Another object of myinvention is to provide a reciprocativespring controlled plunger having a resetting arm extending from one end, with means associated with the arm and plunger whereby a percussion cap can isunder control ofa sounding of be fired bythe plunger coincident with the p a bell undercontrol ofthe re Ysettingarm. c a 7 Another object of my invention is to provide a reciprocative lock and releasefinger in connection with the plunger, which finger cam, detachably secured to the knob shank of a door.

With the above and other minor objects in View, the invention consists in certain peculiarities of construction and combination of parts, as are hereinafter set forth with reference to the accompanying drawings and subsequently claimed;

In the drawings: Figure 1 represents a front elevation of a fragment of a door and its knob equipped with an alinement mechanism embodyingthe features of my invention, with parts broken away and other parts in section to more clearly illustrate details of construction, and ig. 2 is a longitudinal sectional view through the same, the section being indicated by line 22 of Fig. 1.

Referring by characters to the drawings, 1 represents a standard door knob provided with a shank 1 mounted upon which shank is a stirrup cam 2, the same being in the BURGLAR-ALARM,

Specification of Letters Patent. Application filed February 28, 1921.

Wiscons n, Ass e von or ONE-THIRD '10 TO, JAMES EdOCONNELLQBOTH or MIL- Patented May 24, 1921.

Serial No. 448,441. i

form of a spanner arran ed for adjustment upon the knob shank. ne arm 2 of the ,aspanner' has fitted therein a set screw .3, which serves to bind thei'cam-to the shank. I The upper face of the cam is flattened as indicated at 2, and thisfiattened fface is formed with a central recess into which is fitted a nipple 4 thatextends from the lower flattened face of a shoe 5, which shoe constitutes a part of a reciprocative lock, and release finger 6. 1

As bestshown in,Fig.-2,the upper end of the finger is formed with a looped head 6, j the loopin which head is rovided with a 7 key receiving recess '6;'.' he 100 is arranged to encircle a firing plunger which plunger is both reciprocatively and oscillatorily-mounted inapertured ears 8 8 that constitute part of a bracket 9. The rear end of theplunger is formed with an angularly disposed resetting. arm 7, and the forward end face is adapted to entera percussion cap -socket 1 0 of alug 101', the bracket base.

The bracket 9 is secured by suitable means to the door just above the knob, as shown, andj said-bracket has secured thereto, in this particular .case,1a, spring controlled bell 11, said bell being of controlled hammer is released by'abutton 11. The actuating parts of this'bell are 2 not shown,=as they; form 'no partof my invention.; The button, 11, however, is arranged to be engagedby the resetting arm 7 when the alarm is released for an audible signal. The plunger is under spring control and has fitted thereon a coil spring 12, one end of which coil spring abuts the rear bracket ear 8, and the forward end impinges against a collar 13 that is suitably secured to the plunger. Directly forward of the collar, the plunger has extended therefrom a key 14, which key, when the plunger is retracted and looked under sprin pressure, impinges against one face of the nger head 6 whereby the finger is frictionally held in place by the spring ressure against the front ear bracket 8. l ence, it will be noted that when the parts are in their set or locked position, as shown in Fig. 1 of the drawings, should the door knob be rotated in either direction, the flat cam face 2 will rockingly engage the lower face of the shoe 5, which constitutes a part of the finger, and said finger will which extends from thereby be pushed upwardly. This action causes the loop in the head 6 to shift its position, whereby the key 14 of the plunger 7 is free to shoot forwardunder spring pres;

sure, and thismovement'will simultaneously explode a percussion cap that maybe inserted in the lug 10', and release the alarms.

bell 11, due to the fact that the resetting arm 7 "of the plungervvill engage the button 11' of the bell. i

In order to reset the mechanism, after the alarm has been sounded, the operator swings the resetting handle through approximately degrees, whereby the key 14:

of the plunger 7 "will be alined with the recess 6 of the looped aperturein'the head 6. The plunger can "then be drawn back to its resetting position and when it is again revolved about its axis through approximately 425 degrees, the key lei will be blocked against forward movement under spring pressure and the resetting arm will position in alinement with the bell button. Thus, the parts are set; and ready to be tripped, should the knob be revolved in either directon thereafter.

It will also be noted that the nipple 4:

I which extends into the socket of the cam serves as a guide or retaining means for the lock and release'finger, whereby the same is held in-normal alinement. Obviously, I may in 'some instances connect the actuating cam of the alarm with a window,by i means of a runner trained oversultable pulsociated therewith comprising a'braoket having alined apertured ears and an explosive cap lug, a plunger rotatably and slidably mounted in the apertures, the punger having a resetting armiextending from one end, a collar secured to the plunger, a coil spring surrounding the plunger between the collar and one ofthe bracket ears,- a-key extending from said plunger, a reciprocative lock andrelease -finger having a looped head through which the plunger extends, the looped head being providedwith a key away which is normally offset from the line of travel of'the plunger key, and an act-uating cam for 'the lock and "release finger,

the samekbeingdetachably secured tothe shank of the'knob.

2; In a door'having a rotary knobshank; the combination of an alarm associated therewith comprising a bracket having an audible signal mechanism associated there with, ears extending from the bracket, a spring controlled plunger reciprocatively mounted in the ears, a reciprocative lock and releasefinger. having a looped. end through "which the plunger extends, the loop being provided with a key recess, a key carried the plunger, the-same being normally 1n frictional; contact with one face of the fin- 'gerhead, means associated with the {door knob for lifting the finger, wherebythekey is free to travel through the looped head thereof, the forward movement of the plumger being arranged to actuate the audible signal, and a resetting arm extending from the plunger whereby it is rotated in a re-' setting movement to cause the 'key to aline with the loop recess of said finger head.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee,

in the'countyof Milwaukee andState of" Wisconsin.

J S. SPIBEWKA, J R. 

